package com.lxyk.yygh.common.helper;


import io.jsonwebtoken.*;
import org.springframework.util.StringUtils;

import java.util.Date;

public class JwtHelper {

    //固定值，可以自定义
    //token过期时间
    private static long tokenExpiration=24*60*60*1000;

    //token签名的密钥
    private static  String tokenSignKey="wanfeng";

    //根据参数生成字符串
    public static String createToken(Long userId,String userName){

        String token= Jwts.builder().setSubject("YYGH-USER")
                .setExpiration(new Date(System.currentTimeMillis()+tokenExpiration))
                .claim("userId",userId)
                .claim("userName",userName)
                .signWith(SignatureAlgorithm.HS512,tokenSignKey)
                .compressWith(CompressionCodecs.GZIP)
                .compact();
        return token;
    }

    //根据token字符串得到用户id
    public static Long getUserId(String token) {
        if(StringUtils.isEmpty(token)) return null;
        Jws<Claims> claimsJws = Jwts.parser().setSigningKey(tokenSignKey).parseClaimsJws(token);
        Claims claims = claimsJws.getBody();
        Integer userId = (Integer)claims.get("userId");
        return userId.longValue();
    }

    //根据token字符串得到用户name
    public static String getUserName(String token) {
        if(StringUtils.isEmpty(token)) return "";
        Jws<Claims> claimsJws
                = Jwts.parser().setSigningKey(tokenSignKey).parseClaimsJws(token);
        Claims claims = claimsJws.getBody();
        return (String)claims.get("userName");
    }

    //测试
    public static void main(String[] args) {
        String token = JwtHelper.createToken(1L, "wanfeng");
        System.out.println(token);
        System.out.println(JwtHelper.getUserId(token));
        System.out.println(JwtHelper.getUserName(token));
    }


}
